It is known to rid the air from pollutants by way of absorption, adsorption and catalyst masses. Sorption masses depend for their capacity very much on the water vapor partial pressure and, in fact, the capacity of activated charcoal to sorb a number of materials difficult to dissolve in water drops if the relative humidity of the air is above 50 percent, such that in part materials absorbed in this range are already released again.
Catalyst masses become useless even/at very small relative humidities. In order to protect catalyst masses against changes in humidity level they have to be heated up.
In a heated state, however, sorption masses and in particular absorption masses have poor sorption properties, or part of the sorbed pollutants can be released again. Thus a preheating of the air to be cleaned with simultaneous application of sorption and catalyst effective masses has proven to be unsuitable because of the counter production behavior, since the preheating did not lead to the desired success.